Lamp-socket.



'0. WINSTON.

LAMP SOCKET.

APPLICATION FILED MAYB. 1916.

1,280,927. Patented Oct. 8, 1918.

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OVERTON WINSTON, OF MINNEAPOLIS, MINNESOTA.

LAMP-SOCKET.

Specification of Letters Patent.

Patented Oct. 8, 1918.

Application filed May 8, 1916. SeriaI No. 96,161.

To all whom it may concern:

Be it known that I, OVERTON WINSTON, a citizen of the United States,residing at Minneapolis, in the county of Hennepin and State ofMinnesota, have invented certain new and useful Improvements in Lamp-Sockets; and I do hereby declare the following to be a full, clear, andexact description of the invention, such as will enable others skilledin the artto which it appertains to and in my pending application S. N.94,617

filed of date May 1st, 1916 and entitled Headlight socket.

The invention is illustrated in the accompanying drawings wherein likecharacters indicate like parts throughout the several views.

Referring to the drawings:

Figure 1 is a vertical section taken through the improved socket andshowing the electric light bulb held thereby; and

Fig. 2 is a similar view illustrating a slightly modified construction.

The numeral 1 indicates an electric light bulb of the double-base orthree-contact type, such, for example, as that illustrated in my pendingapplicatlon 91,226. A bulb of this character has three contacts 2, 3 and4. The outer contact 2 is in the form of a metallic sleeve whichsurrounds the shank of the lamp. The contact 3 is in the form of a metalring applied to the end of the shank, and the contact 4 is in the formof a small metallic disk located at the axis of the shank. The saidcontacts 2, 3 and 4 are insulated from each other, by the insulatingmaterial of which the shank is made. The contact sleeve 2 has aplurality, as shown, two, radially projecting lock lugs 5, for a purposewhich will presently appear.

The contact sleeve 2 of the bulb is adapted to be telescoped into aholding collar 6 that' is provided with an externally-threaded eccentric6*. The lugs 5 of the shank contact collar 2 are adapted to be insertedthrough internal grooves 7 in the holding collar 6 and turned intoengagement with a corru gated internal shoulder 8 of said collar.

The said parts 7 and 8 are indicated by dotted lines only, but are morefully disclosed in my prior application S- N. 86,851 filed of date,March 27th, 1916, and entitled Headlights.

The externally threaded eccentric 6 of the holding collar is screwedinto the internal threads 9* of a socket sleeve 9 in the rear end ofwhich is an insulating plug 10. The insulating plug 10 has a forwardlyspringpressed axially projecting contact plunger 11, the head of whichengages the axial contact 4 of the light bulb, when the latter is inposition. The so-called holding collar 6 and sleeve 9 constitute anadjustable lamp socket, and by rotary adjustment of said collar, and itsthreaded eccentric, the light bulb may be adjusted both longitudinallyand transversely of the axis of the socket, and hence, of the axis ofthe reflector, not shown, but which will usually be employed inheadlights where the socket is applied.

The metallic head of the contact plunger 11.

is provided with a rigidly secured surrounding collar 12 of insulatingmaterial, the purpose of which will presently appear.

The numeral 13 mdicates a so-called centering sleeve which is ofinsulating material, and 1s telescoped into and rigidly secured to theeccentric 6, so that it rotates therewithl. This collar 13 is also, asshown, formed with external threads that engage with the internalthreads 9 of the sleeve 9. The rear portion of the passage through thecentering ring or sleeve 13 is enlarged to form a shoulder against whicha metallic washer 14 is seated. This washer has a large axial opening sothat it does not come into contact with the contact plunger 11 or itsspring, and it is held seated by a coiled tension spring 15 compressedbetween the same and the insulating plug 10 and surrounding the hub onthe latter. This spring exerts an end thrust on the members 6 and 13,which increases the frictional tension between the threads thereof andthe threads 9' of the sleeve 9, and thereby assists in preventingaccidental rotation of said eccentric. A smaller coiled spring 16closely fits within the front end portion of the centering collar 13 andis compressed between the washer 14 and contact ring 3. The spring 15will have a greater tension than the spring 16, so that the washer 14will always be held seated. The spring 16 makes electrical contactbetween the washer 14 and the ring 3 and also serves to hold the lugsengaged with the shoulder 8 and hence, holds the light bulb againstaccidental rotation. The socket shown, as stated, is for a three-contactlamp, and hence, of the three leads of the lightlng circuit, the lead 17is connected to the contact plunger 11, the lead 18 is connected to themetallic washer 14, either directly, or,

an axial passage that is concentric to the as shown, through the spring15, and the lead 19 is grounded through the socket sleeve 9 and collar6, which latter has electrical contact with the contact sleeve 2 of thebulb shank. The insulating collar 12 keeps the head of the contactplunger 11 always out of electrical contact with the spring 16.

The above described centering sleeve 13 has an eccentric passage that isconcentric to the axis ofthe sleeve 9, but eccentric to the axis of theholding collar 6 and the shank of the light bulb. In Fig. 2, however, asimilar insulating centering collar 14L has axis of the holding collar 6and shank of the light bulb, but eccentric to the axis of the socketring or sleeve 9. Into this centering sleeve 14 is inserted and secureda metallic bushing 20, to which one end of a spring 16 is secured bysolder, or otherwise. The front end of this spring 16 is held inelectrical contact with the contact ring 3 of the light bulb. Thebushing 20 is formed with a shoulder between which, and the insulatingplug 10, a tension spring 15 is compressed. This spring 15, like thespring 15, exerts a tension which assists in holding the eccentric 6,and hence, the light bulb against accidental rotation.

The metal washer 14: shown in Fig. 1 serves as an abutment against whichthe springs 15 and 16 re-act, and the metal bushing 20, shown in Fig. 2,afi'ords an abutment against which the springs 15 and 16 memes? react,and hence, these two elements may portion screwed into the internalthreads of said sleeve, an insulating centering ring secured within saidcollar, an annular metallic abutment seated against said centering ring,a contact spring reacting against said abutment and projecting throughsaid centering ring for engagement with one of the lamp contacts, and atension spring seated against said insulating plug and against saidannular abutment.

2. In a lamp socket, the combinationwith an internally threaded metallicsocket sleeve having an insulating plug in its rear end,

of a lamp holding collar having a threaded eccentric screwed into theinternal threads of said sleeve, an insulating centering ring securedto-said eccentric, an annular metallic abutment seated against saidcentering ring,

a contact spring reacting against said abutment and projecting throughsaid centering ring for engagement with oneof the lamp contacts, and atension spring seated against said insulating plug and. against saidannular abutment.

In testimony whereof I aflix my sigature in presence of two witnesses.

OVERTON WINSTON.

Witnesses CLARA DEMAREs'r,

B. G. Wnnarnn.

